METHODS FOR SELECTIVE RECOVERY OF RARE EARTHS IN AQUEOUS ACID PHASES RESULTING FROM THE TREATMENT OF PERMANENT MAGNETS USED OR REBUIDED

摘要

The invention relates to a hydrometallurgical process for selectively recovering at least one rare earth "heavy", that is to say of atomic number at least equal to 62, being in an acidic aqueous phase resulting from the treatment of used or rejected permanent magnets. It also relates to a hydrometallurgical process for selectively recovering, at first, at least one heavy rare earth present in an aqueous acid phase resulting from the treatment of used or discarded permanent magnets, and then, at a second stage, at least one rare earth "light", that is to say, atomic number at most equal to 61, also being in this aqueous acid phase. The invention finds particular application in the recycling of rare earths present in used or rejected scraped Neodymium-Iron-Boron permanent magnets (or NdFeB) and, in particular, dysprosium, praseodymium and neodymium, as well as in recycling Samarium present in permanent magnets Samarium-Cobalt type (or SmCo) used or rejected.